A line of strong thunderstorms moved from east central Wisconsin over the near shore waters of Lake Michigan around Sheboygan.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MKX wrote it up.
A line of strong thunderstorms moved from east central Wisconsin over the near shore waters of Lake Michigan around Sheboygan.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Milwaukee, WI wrote its last area forecast discussion before the first event at Aug 21, 2:40 PM CST, 5 hours 31 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 340 PM CDT WED AUG 21 2013 .VERY SHORT TERM...TONIGHT AND THURSDAY. CONVECTION IS FIRING UP ALONG THE SURFACE COLD FRONT FROM NORTHWEST WI THROUGH THE TWIN CITIES AREA. THIS LINES UP WELL WITH THE NCEP 4KM WRF-NMM SIMULATED RADAR REFLECTIVITY. THAT MODEL BRINGS A LINE OF CONVECTION SOUTHEAST INTO THE MKX FORECAST AREA 01Z-02Z...THEN ALLOWS IT TO WEAKEN. IT SHOWS A SLIGHTLY STRONGER AREA OF CONVECTION CONTINUING IN SOUTHEAST WI BUT MUCH LESS CONVECTION IN SOUTH CENTRAL WI. SOME OF THE OTHER MODELS ARE SHOWING THIS SPLIT AS WELL..SO IT WILL BE SOMETHING TO WATCH OUT FOR. MEANWHILE...THE 18Z HRRR MODEL RUN SHOWS THAT CONVECTION IN NORTHWEST WI...BRINGS IT EASTWARD AS A BLOB...AND NEVER EXTENDS ANY CONVECTION DOWN INTO SOUTHERN WI AT ALL. MOST CONVECTION WILL LIKELY BE ALONG THE IL BORDER BY 06Z AND ENDING SHORTLY THEREAFTER. MID LEVEL DRY AIR MOVES IN QUICKLY BEHIND THE FRONT AND ANY SEVERE THREAT WILL BE GONE BY 06Z. AS FOR SEVERE POTENTIAL...THE BEST RISK OF SEVERE WEATHER WILL BE OVER NORTH CENTRAL WI. THIS IS WHERE THE SPC STORM SCALE ENSEMBLE OF OPPORTUNITY BULLSEYES THE HIGHEST 24-HOUR PROBABILITY OF HIGH UPDRAFT HELICITY AND HIGH UPDRAFT SPEED. THIS IS ALSO WHERE THERE IS A SEVERE THUNDERSTORM WATCH IN EFFECT RIGHT NOW. SPC HAS THE SLIGHT RISK INCLUDING MADISON AND WEST BEND. THIS SEEMS REASONABLE BASED ON MODEL FORECAST REFLECTIVITIES. ANY STRONGER AND ORGANIZED STORMS THAT DEVELOP OVER CENTRAL WI COULD SWEEP SOUTH AND SOUTHEAST WITH A DAMAGING STRAIGHT-LINE WIND THREAT INTO THE NORTHERN MKX FORECAST AREA. WITH CAPE VALUES EXCEEDING 3000 J/KG AND MODERATE 0-3 AND 0-6KM SHEAR...LARGE HAIL WILL BE POSSIBLE AS WELL. AS STORMS MAKE IT FURTHER INTO SOUTH CENTRAL AND SOUTHEAST WI LATER THIS EVENING...SURFACE BASED CAPE AND BULK SHEAR VALUES DECREASE GIVEN THE TIME OF DAY AND THE SURFACE TROUGH LOSING DEFINITION. ALSO THE 850MB LEADING EDGE OF THE LOW LEVEL JET AND WARM AIR ADVECTION WILL BE SHIFTING EAST OVER LAKE MICHIGAN. THERE IS ANOTHER SHORTWAVE THAT WILL TRACK ALONG THE 850MB BAROCLINIC ZONE THROUGH NORTHERN IOWA AND EVENTUALLY INTO NORTHERN IL LATE TONIGHT/THU MORNING. CONVECTION WITH THIS FEATURE MAY CLIP SOUTHERN WI SO LEFT A SMALL CHANCE FOR THUNDER THROUGH THU MORNING. SUNSHINE IS EXPECTED LATER THURSDAY...ALLOWING MAX TEMPS IN THE UPPER 70S AND LOWER 80S WITH A NORTH TO NORTHEAST BREEZE. .SHORT TERM...THURSDAY NIGHT THROUGH SATURDAY. A QUIET PERIOD IS ANTICIPATED AS HIGH PRESSURE AT THE SURFACE AND ALOFT CONTINUES TO BUILD INTO THE WESTERN GREAT LAKES TO CENTRAL MS VALLEY. LIGHT WINDS BELOW SHALLOW INVERSION SHOULD ALLOW PATCHY FOG TO DEVELOP IN THE WI RIVER VLY LATER THU NIGHT. BOUNDARY LAYER MIXING JUST ABOVE INVERSION SHOULD PREVENT SIGNIFICANT FOG ELSEWHERE HOWEVER. WARMER AIR STARTS TO RETURN ON SATURDAY AS LOW LEVEL WINDS TURN MORE SOUTH. ANY CONVECTION ASSOCIATED WITH PUSH OF WARM AIR AND WEAK SHORT WAVE IS EXPECTED TO REMAIN TO THE NORTH OF CWA ON SAT. .LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. MEDIUM RANGE GUIDANCE IN GOOD AGREEMENT ON EXPANSIVE HIGH PRESSURE RIDGE OVER SOUTHERN CONUS EXPANDING NORTHWARD AND ENVELOPING SOUTHERN WI ON SATURDAY AND PERSISTING THROUGH THE FIRST PORTION OF NEXT WEEK. 500H HEIGHTS INCREASE TO AROUND 591 METERS WHILE 85H TEMPS INCREASE TO 19 TO 22C. HENCE A VERY WARM PERIOD IS EXPECTED WITH DAYTIME READINGS MOSTLY IN THE UPPER 80S TO MIDDLE 90S. DAYTIME HEAT INDICIES MAY REACH 95 TO 100 SEVERAL DAYS. 500H GFS 5 DAY ANOMOLIES SHOW HEIGHTS 50-70 METERS ABOVE NORMAL THROUGH THE END OF AUGUST...WITH MORE ZONAL FLOW SETTLING OVER NORTHERN CONUS FOR START OF SEPT. STILL A POTENTIAL FOR SEVERAL MID-LEVEL SHORT WAVES BREAKING THROUGH CAPPING INVERSION OVER NORTHERN/CENTRAL WI...WITH CONVECTION CARRYING SWD INTO PORTIONS OF SRN WI FROM SAT NIGHT INTO TUE. MOST OF THE PERIOD WILL REMAIN DRY AND WARM HOWEVER. && .AVIATION /00Z TAFS/...THUNDERSTORMS ARE LIKELY ALONG A COLD FRONT MOVING SOUTHEAST ACROSS CENTRAL AND SOUTHERN WI THIS EVENING. SOME IFR CONDITIONS IN STORMS. STORMS WILL BE MORE WIDESPREAD EARLY THIS EVENING AND THEN BECOME MORE SCATTERED LATER IN THE EVENING. SEVERE THUNDERSTORMS POSSIBLE NORTH OF A LINE FROM PLATTEVILLE TO MADISON TO WEST BEND. DAMAGING WINDS AND SMALL HAIL ARE THE THREATS. SEVERE POTENTIAL DIMINISHES AFTER 06Z AND PRECIP CHANCES DIMINISH SHORTLY THEREAFTER AS WELL. THERE COULD BE A PERIOD OF MVFR CIGS AND VSBYS JUST BEHIND FRONT OVERNIGHT. DRIER AIR WITH WINDS OUT OF THE NORTHEAST WILL SETTLE INTO SOUTHERN WI BY EARLY THU AFTERNOON. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && .CONFIDENCE... TONIGHT AND THURSDAY...MEDIUM TO HIGH. THURSDAY NIGHT THROUGH SATURDAY...HIGH. SATURDAY NIGHT THROUGH WEDNESDAY...MEDIUM. VERY SHORT TERM/AVIATION...MRC SHORT TERM/LONG TERM...MBK
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 630 PM CDT WED AUG 21 2013 WIZ046-047-051-052-056>060-062>072-222330- MARQUETTE-GREEN LAKE-FOND DU LAC-SHEBOYGAN-SAUK-COLUMBIA-DODGE- WASHINGTON-OZAUKEE-IOWA-DANE-JEFFERSON-WAUKESHA-MILWAUKEE- LAFAYETTE-GREEN-ROCK-WALWORTH-RACINE-KENOSHA- 630 PM CDT WED AUG 21 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL WISCONSIN...SOUTH CENTRAL WISCONSIN AND SOUTHEAST WISCONSIN. .DAY ONE...TONIGHT A COLD FRONT WILL SAG THROUGH SOUTHERN WISCONSIN FROM LATE EVENING THROUGH THE OVERNIGHT HOURS. SCATTERED TO NUMEROUS THUNDERSTORMS ARE EXPECTED ALONG THE FRONT. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ROUGHLY ALONG AND NORTH OF A LINE EXTENDING FROM SHEBOYGAN...WEST BEND...MADISON TO DODGEVILLE. DAMAGING WINDS WILL BE THE PRIMARY HAZARD. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH WEDNESDAY THERE IS A SMALL CHANCE OF THUNDERSTORMS THURSDAY MORNING ALONG AND SOUTH OF A LINE FROM MILWAUKEE TO MINERAL POINT. HEAT INDEX READINGS ARE EXPECTED TO REACH THE 90 TO 100 DEGREE RANGE DURING THE DAYS FROM SUNDAY THROUGH TUESDAY. THERE IS A SMALL CHANCE FOR THUNDERSTORMS FROM SUNDAY NIGHT THROUGH TUESDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED TONIGHT. LMZ643>646-222330- SHEBOYGAN TO PORT WASHINGTON WI- PORT WASHINGTON TO NORTH POINT LIGHT WI- NORTH POINT LIGHT TO WIND POINT WI- WIND POINT WI TO WINTHROP HARBOR IL- 630 PM CDT WED AUG 21 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN. .DAY ONE...TONIGHT WINDS AND WAVES WILL CONTINUE TO APPROACH SMALL CRAFT CRITERIA LATE THIS AFTERNOON. THUNDERSTORMS ARE LIKELY TONIGHT AS A COLD FRONT DROPS SOUTHEAST ACROSS LAKE MICHIGAN. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS NORTH OF NORTH POINT LIGHT. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH WEDNESDAY THERE IS A CHANCE OF THUNDERSTORMS THURSDAY MORNING FROM MILWAUKEE SOUTH TO WINTHROP HARBOR. THERE IS A SMALL CHANCE FOR THUNDERSTORMS FROM SUNDAY NIGHT THROUGH TUESDAY. REM WWW.WEATHER.GOV/MKX
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html><!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html><!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html><!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html><!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html><!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html>The Green Bay radar (KGRB), 90 km away, was scanning. The volume nearest the first event began at 02:11 UTC.
2 marine thunderstorm wind. Local standard time, as filed.
The lakeshore observing station at Sheboygan (SGNW3) recorded a wind gust of 43 knots.
The lakeshore observing station at Sheboygan (SGNW3) recorded a wind gust of 43 knots.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Lake Michigan in 2013Every state in 2013This day in weather history
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 467485, 467486.